An asset tracking device is deployed to track the location or other physical properties of an asset as they move between locations. For this purpose, the asset tracking device may include one or more types of sensors that monitor its locations or physical properties and send the monitored results to a remote station. The transmission of the monitored results is often accomplished by wireless communication. The asset tracking device is generally implemented in a small and portable form and includes batteries or other energy sources that provide power while the asset is being transported between locations.
One of the physical properties measured by the asset tracking device is temperature. The asset tracking device may include a temperature sensor to monitor the temperature of a target or its surrounding environment. The asset tracking device, however, generally includes various sources of heat such as circuit components for radio frequency (RF) communication. These components tend to heat up the asset tracking device when active. If the temperature sensor is close to such heat source or connected via non-insulated materials, the heat generated by the heat source tends to interfere with an accurate measurement of the temperature at the temperature sensor by raising the temperature at the temperature sensor. As the asset tracking device becomes more compact, the heat generated by the heat source more significantly affects the temperature measurements.
One solution to mitigating the effects of the heat source on the temperature measurements is to divide up the asset tracking device into two multiple physical parts. A first part includes a temperature sensor and is placed within or proximate to the target whose temperature is being measured. A second part is physically separate from the first part, and hence, the effect of heat from the second part is reduced. The first part communicates with the second part via short-range RF communication or wired communication to transmit monitored result to the second part without generating significant heat within the first part. The second part includes RF components for a long-range communication to transmit the data to a remote monitoring station. The RF components in the second part generate significant amount of heat, but the heat from the second part does not or has a minimal effect on the temperature measured at the first part because the heat from the second part is only partially transmitted to the first part.
However, the solution of implementing the asset tracking device into two parts may significantly limit the physical locations of the asset tracking device due to the communication range of the short-range RF communication or the lengths of the wire. The asset tracking device with wired communication also requires external wire ports at the first and second parts, and complicating the packaging of the asset due to the wire.